Fuel injection nozzle



May 30, 1961 E. s. BAH.. 2,986,342

FUEL INJECTION NOZZLE Filed Feb. 4, 1959 5Z- u I df%' Q f5 Q "i g j IZ fl.. v ll; 5%-- l Il 22,* I|,I

25* i ,f2-* 1 .f5-if 2 a" 1 I 4 gir" 30 'I .Z3 fnz/ezzfof: y I Einar* j. czfal' United States Patent FUEL INJECTION NOZZLE Einar S. Dahl, Decatur, Ill., assignor to Borg-Warner Corporation, Chicago, Ill., a corporation of vIllinois FiledFeb. 4, 1959, Ser. No. 791,217

7 Claims. 239-453) This invention relates to a spray type'fuel injection nozzle ,particularly adapted to inject fuel into the air intake manifold of an internal combustion engine.

It is an object of the present invention to provide a fuel injection nozzle that is simple in construction, inexpensive to manufacture, and uniformly reliable in performance.

' It is `another object to provide a fuel injection nozzle that is easily assembled'and calibrated for a desired opening pressure and adapted for mass production methods of manufacture.

More particularly, it is an lobject of the present invention Ato provide la nozzle vthat is finally lassembled and calibrated vfor `a desired opening pressure by one simple external operation.'

"lltfis amore `particular object to vprovide a fuel injection nozzlehaviug a cylindrical body or tube, a spring 'loaded lvalve stem, a nozzle tip, and a double screw advance mechanism for simultaneously mounting the nozzle tip and valve stem within the tube and adjusting the opening `pressure of the valve Stem.

The invention consists of the novel constructions, arrangements, and devices tobe hereinafter described and claimed for carrying out the above stated objects and such other objects as will appear from the following description of `a preferred form of the invention, illusftited with reference `to the accompanying drawings wherein:

Fig. 1 is a longitudinal sectional view of the improved -fuel injection nozzle of the present invention; and

` tFigs. 2, 3, and `4 are views taken respectively on lines 2 2, 3 3, and 4f4 vof Fig. l.

Like characters of reference designate like parts in the Several vews. t l

Referring now to Fig. l, the improved fuel injection nozzle of the present invention is designated generally by the numeral 10. 'The nozzle 10 comprises a cylindrical tube or body v11, a nozzle tip 12, a valve stem I3, av spring 14, and a spring seat 1S. The nozzle tube 11 is formed with a longitudinal fuel passage comprising a central cylindrical bore 16, a relatively larger connected bore 17 on one end for receiving the nozzle tip 12, and a still larger connected bore 18 on the other end for connecting the nozzle to a fuel supply line.

The bore "liis'threaded on its interior at 19 with a screw thread of relatively large pitch. The `bore 17 is threaded on its interior Aat `Ztwith `a screw thread of a relatively smaller pitch. The spring seat is generally cylindrical in 'shape and is formed on its exterior with threads 21 adapted to mesh with the threads 19. The nozzle tip 12 is also generally cylindrical in shape and is formed on a portion of its exterior with threads 22 adapted to mesh with the threads 20. The spring seat 15 is also formed with an axial central bore 23 and external parallel at surfaces 24. The nozzle tip 12 is yformed 70 with a transverse slot 25 which receives the at surfaces 24 of the spring seat 15. The nozzle tip 12 is also formed Patented May 30, 1951 with an axial central bore 26 through which the valve stem 13 extends, an external Vannular groove 27 for receiving an :0 ring 28, and two 'longitudinal grooves v29. 'The centralbore 26 is ared at 30 so as to form a vseat for the valve stem 13.

The valve vstern r13 is formed with an integral hemispherical head 31 on one end an an integral cylindrical collar 32 on the other end thereof. The hemispherical head 31 is vadapted to form a fluid tight seal against the seat' 30 ofthe nozzle tip 1-2. The head 31 is also formed with @a ared outer edge or skirt 33 which defines a con- 4stant spray angle for the fuely discharged by the nozzle YI10.

A spring retaining cap 34 is provided with a cylindrical recess 3S for receiving the collar 32 and a radial slot 36 for embracing the valve stem 13. The spring 14 surrounds the valve stem 13 and is disposed under compressionlbetween the retaining cap 34 and a cylindrical recess 37 formed in thespring seat ,15.

The nozzle 10 also includes a screen strainer 38, ya liltering felt 39, and a spring y40 for retaining the felt 39 within the bore 18. The bore '18 is threaded on its interior at 41 for connecting the nozzle to a fuel supply line.

4'In assembling the nozzle for use, the 0 ring 28 is placed inthe annular groove 27 of the nozzle tip 12 and the valve stem 13 is inserted through the central bore Y26 of the nozzle tip 12 and through the central bore 23 of the spring seat 15. The spring 14 is placed on the valve stem '13 'over the collar 32 is compressed slightly, and the retaining cap 34 is inserted radially with the slot "36 'engaging the valve lstem 13. The spring 14 is then released `and "it forces the retaining cap axially so that the c o'llar32 enters the recess 35 and the'head 31 'is forced Uagainst V-the seat 30.

` The nozzle '-tip"-12,\valve stem 13, spring 14, and spring seat'15 are now ready for assembly as a unit into the tube 11. `The Avalve `stem 13 Vis inserted into the nozzle tube 11 with the collar 32 yfirst so that the threads 21 of the -spring seat 15 engage thethreads 19 within the bore 1'6, and the threads 22 engage the threads 2) within the bore 17.

A Spanner type wrench having radial teeth that engage the longitudinal slots -29is utilized for turning the nozzle tip 12'within the tube 11. As the nozzle tip 12 is turned clockwise, "the turning torque is transmitted throughslot 25 and flat surfaces 24 so as to turn the spring seat 15 as well. The difference in pitch-of the threads 21 and 22 causes the spring seat 15 to advance at a greater `rate than the Vnozzle tip 12, thereby compressing the spring I4. i vThe nozzle body 11 'may be screwed onto ka source of fluid pressure, and the nozzle tip 12 can be turned within the nozzle "tip 11 compressing the spring 14 until a desired 'opening'pressure for the valve head 3l is obtained. The screen 38, felt 39, and spring 40 are inserted and the nozzle is completely assembled and ready for use.A

The O ring 28 functions both as a seal and as a locking member for Vlocking the position of the nozzle tip 12 within the tube 11. If desired, the end of the nozzle tube 11 can be crimped into the longitudinal grooves`29 to insure that the angular position of the nozzle tip .12 with respect `to't'he tube 11 does not change.

lThere has been `provided by this invention a fuel injection nozzle that is inexpensive, simple in construction, and easily assembled and calibrated for a desired opening pressure; Nozzles'producedaccording lto this invention will be uniform in performance and operating characteristics and should require no further adjustment or calibration for operation in a fuel injection system.

It is to be understood that this invention is not to be limited to the specific constructions and arrangements shown and described except only insofar as the appended claims may be so limited, as it will be apparent to those skilled in the art that changes may be made without departing from the principles of the invention.

I claim:

1. In a fuel injection nozzle having a tubelike body, a nozzle tip adjustably mounted within the body, a valve disposed within said nozzle tip and a spring for holding said valve in a fluid ceiling position against said tip, the combination of spring adjusting means adapted to be adjustably mounted within the body, means for mounting the nozzle tip within said body, and differential motion transmitting means drivingly interconnecting said nozzle vtip with said spring adjusting means for establishing a reaction force within said spring whereby the opening pressure of the valve may be calibrated by the same operation as that by which the nozzle tip is mounted within the body.

2. In a fuel injection nozzle, the combination of a tubelike body formed with a longitudinal fuel passage therethrough, a nozzle tip adapted to be adjustably mounted within the body and also formed with a fuel passage therethrough, a valve disposed within the fuel passage of said nozzle tip and adapted to form a uidtight seal on one end thereof, a spring acting on said valve for maintaining it in fluid sealing position below some predetermined opening pressure, spring adjusting means also adapted to be mounted within said body, means for drivingly interconnecting said spring adjusting means with said nozzle tip, and means for advancing said spring adjusting means at a greater rate than said nozzle tip is advanced when mounting the nozzle tip within said body, whereby the opening pressure of said valve can be calibrated by adjustment of said nozzle tip.

3. In a fuel injection nozzle, the combination of a tubelike body having a longitudinal fuel passage therethrough to one end of which fuel under pressure is adapted to be supplied, a threaded nozzle tip formed with a fuel passage defining a valve seat on one end thereof and vadjustably threaded within said body, a valve extending into said fuel passages, spring means attached to said valve for forcing it against said seat, and threaded spring adjusting means interconnected with said nozzle tip and said spring and adapted to be threaded within said body,`

4. In a fuel injection nozzle, the combination of a tubular body having a longitudinal fuel passage that is threaded on its interior with rst threads on a relatively large pitch and with second threads of a comparatively smaller pitch; a spring seat comprising a sleeve-like body formed on its exterior with threads of comparatively large pitch for engaging said first threads of said body; a nozzle tip formed with a longitudinal fuel passage therethrough and threads on its exterior of comparatively small pitch for engaging said second threads of said body; means for drivingly connecting said nozzle tip to said spring seat; a valve extending through the fuel passage of said nozzle tip and adapted to form a fluidtight seal on one end thereof below some predetermined opening pressure; and a spring surrounding said valve and 'disposed under compression between said spring seat and an inner end of said valve, whereby said spring seat and said nozzle tip can be threaded simultaneously within said nozzle body with said spring seat advancing at a greater rate than said nozzle tip for thereby compressing 4 said spring and adjusting the opening pressure of said valve as said nozzle tip is threaded within said body.

5. In a fuel injection nozzle, the combination of a tubelike body member having a longitudinal fuel passage therethrough that is formed throughout a portion of its length with threads of relatively large pitch, said passage also being enlarged at one end of the body and threaded on its interior with threads of comparatively smaller pitch; a nozzle tip formed with a fuel passage therethrough and threaded on its exterior for a portion of its length, said nozzle tip also being formed with a transverse slot on an inner end thereof; means defining a valve seat on the outer end of said nozzle tip fuel passage; a valve extending through said nozzle tip and adapted to form a fluid-tight seal against said seat; spring means surrounding said valve for forcing said valve against said seat; and a spring compression adjusting seat comprising a sleeve-like member formed on its exterior with threads of comparatively large pitch and external parallel flat surfaces adapted to engage the transverse slot of said nozzle tip, said spring adjusting seat and said nozzle tip being adapted to be threaded simultaneously into said nozzle body with the threads of said spring seat engaging said first named threads and the threads of said nozzle tip engaging said last named threads with said spring seat advancing at a greater rate than said nozzle tip for thereby compressing said spring as said nozzle tip is threaded into said body.

6. In a fuel injection nozzle, the combination of a tnbelike body having a longitudinal fuel passage therethrough, a nozzle tip formed with a fuel passage defining a seat on one end thereof and adjustably mounted within said body, a valve extending into said fuel passage and adapted to form a fluid-tight seal against said seat below some predetermined opening pressure, spring means connected to said valve for forcing it against said seat, spring adjusting means mounted within said body and adapted to act on said spring, and differential motion transmitting means interconnecting said nozzle tip and said spring adjusting means whereby the force of said spring means and opening pressure of said valve can be adjusted by external adjustment of said nozzle tip.

7. In a liquid spray type nozzle, the combination of a tueblike body having a longitudinal liquid passage therethrough and to one end of which liquid under pressure can be supplied, a nozzle tip adjustably mounted within said body and formed with a longitudinal liquid passage dening a valve seat on one end thereof, a valve extending into said passage and adapted to form a fluid-tight seal against said seat below some predetermined opening pressure, adjustable spring means acting against said valve and effective to determine the opening pressure thereof, spring adjusting means mounted within said body and interconnected with said nozzle tip and acting on said spring means, and differential motion transmitting means forward integrally with said nozzle tip and said spring adjusting means whereby the opening pressure of said valve can be calibrated by external adjustment of said nozzle tip.

References Cited in the tile of this patent UNITED STATES PATENTS 551,938 Travis Dec. 24, 1895 1,112,416 Sargent Sept. 29, 1914 2,743,962 Dressler May l, 1956 2,893,647 Wortman July 7, 1959 FOREIGN PATENTS 839,831 France Ian. 7, 1939 

